Heretofore, various techniques have been developed to eliminate the costly and labor intensive cut and sew methods of joining two or more layers of sheet-like material, such as cloth, fabric or the like. One known technique employs contact adhesive which is applied to one of the layers of material to form an adhesive bond therebetween. However, once the adhesive is applied it is difficult to position the layers of material relative to one another without a degree of misalignment. Furthermore, the resulting product is often flawed with undesirable wrinkles.
It is also known to apply dielectric heating to a heat-sensitive material placed between two materials to effectuate bonding therebetween. While dielectric heating has proven to be satisfactory for bonding materials including a closed-cell structure, such as vinyl and the like, difficulties are encounter when one or both of the materials to be bonded have an open-cell structure, such as fabric. The high energy electric environment necessary to sufficiently actuate typical heat-sensitive adhesives is susceptible to arcing when used in connection with porous materials.
Another known technique, commonly referred to as "hot sealing", includes disposing a heat-sensitive adhesive sheet or film between two portions of fabric and melting the adhesive to effectuate bonding with a heated pressing mold in contact with the fabric. Disadvantageously, this technique often results in nonuniform bonding due to uneven temperature distribution throughout the layer of adhesive. Additionally disadvantageous, many fabric types which are otherwise well suited for soft trim products are made from materials which cannot withstand the high temperature ranges necessary to sufficiently activate the adhesive and join the fabrics. As a result, these otherwise desirable materials are rendered unusable. In this regard, the integrity of the strength of a fabric and other physical properties are often susceptible to degradation when exposed to the high temperatures necessary to effectuate proper bonding. For example, many fabrics are subject to color changes when exposed to mold temperatures in excess of 260.degree. F. Furthermore, a heated tool or press that is utilized to melt heat-sensitive adhesive between layers of fabric is generally removed from the material while the adhesive is in at least a partial liquid state. As a result, the materials intended for bonding are subject to separation prior to complete setting of the adhesive.
While previously known techniques have proven to be relatively commercially acceptable for a wide range of applications, each is attendant with inherit limitations, some of which have been discussed above. In addition, many prior techniques are complex, cost prohibitive, or both.
Accordingly, it is desired to provide a cost effective method of manufacturing a soft trim product that is applicable for use with a wide range of materials.